Hydrophilic endodontic sealing compositions and methods for using such compositions

ABSTRACT

A root canal is filled and/or sealed using a hydrophilic sealing composition, optionally in combination with other filling materials. The sealing composition may include one or more resins that promote adhesion to hydrophilic dental tissues. The composition may be introduced into the root canal using a narrow cannula coupled to a high pressure hydraulic delivery device. In the case where a chemical cure composition is used to seal the root canal, a chemical initiator can be used to cause the mixed composition to harden over time. Hardening of at least a portion of the composition can be accelerated by including a photoinitiator and irratiating the mixed composition with radiant energy (e.g., from a dental curing lamp).

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.10/128,970, filed Apr. 23, 2002, now abandoned the disclosure of whichis incorporated in its entirety.

BACKGROUND OF THE INVENTION

1. The Field of the Invention

The invention is in the field of compositions and methods for sealing aroot canal during an endodontic procedure. More particularly, theinvention involves compositions having enhanced adhesion to hydrophilicdental tissues found within root canals which assists their ability toeffectively seal and protect a newly cleaned root canal. Suchcompositions are preferably radiopaque and are cured more rapidlycompared to conventional endodontic sealing compositions, thus allowingfor quicker placement of a final filling or crown to complete the rootcanal procedure.

2. The Relevant Technology

Following an endodontic root canal procedure, in which the root canal iscleaned using special root canal tools and irrigation devices, it isimportant to fill and seal the evacuated root canal in order to preservethe dead tooth from further decay that might compromise the integrity ofthe tooth and cause infection. In a typical procedure, one or more soft,resilient, needle-like inserts known as “gutta percha” points areinserted in each root canal branch in order to at least partially sealand fill the root canal.

The term “gutta percha” refers to a rubbery material derived fromnatural rubber, typically blended with zinc oxide. This particularrubbery material is preferred because it is compressible, flexible andrelatively soft so that it can be used to fill voids within the exposedroot canal. The gutta percha points are typically impregnated with othermaterials such as radiopaque solids, zinc oxide, for its medicinalproperties, and other passive or active ingredients as desired. It isimpossible, however, to completely seal a root canal from all ingress offluids, which may be laden with bacteria, using gutta percha alone.Conventional techniques require multiple gutta percha cones per canaland laborious “later condensation” techniques. For some, it requiresheating the gutta percha in an attempt to make it flow into the lateralcanals. However, this technique, coupled with the properties of guttapercha, make it hard to achieve fine adaptation to canal walls and flowinto the dentinal tubules.

The filling and sealing of the root canal can be further enhanced byinserting flowable materials, such as antiseptic pastes and/or sealingresins along with the gutta percha points. Due to the high viscosity oftypical antiseptic pastes, such as zinc oxide/eugenol, or sealingresins, which tend to be epoxy-based, such materials are first appliedto the gutta percha and then inserted into the root canal along witheach gutta percha point. Alternatively, they may be inserted using alentalo applicator. In this manner, it is hoped that the remainingspaces between the gutta percha points and the root canal can be filledwith the antiseptic paste or resin. In addition, it is hoped that theepoxy-based resin will help to seal the root canal.

One of the drawbacks of using conventional pastes or resins is that suchmaterials tend to be hydrophobic. This renders such materials somewhatincompatible with dental tissues within the root canal, which are highlymineralized, somewhat moist and therefore extremely hydrophilic. Thehydrophilic nature of the root canal environment inhibits wetting andadhesion of the root canal by hydrophobic materials. As a result,conventional antiseptic pastes and epoxy-based resins actually form apoor seal between the gutta percha points and the walls of the rootcanal, thus potentially providing access for microbes and infection.

A further problem of conventional antiseptic pastes and epoxy-basedendodontic sealing resins are their inability to adequately penetrateinto, wet and seal the lateral canals which extend laterally from theroot canal into the root of the tooth. Occasionally, the inability toseal the lateral fissures using conventional pastes and/or epoxy-basedresins creates one more place where microbes may establish a beach headand be capable of festering over time.

In addition to the inability of the antiseptic pastes or epoxy-basedresins to adequately adhere to and seal the root canals and lateralfissures, another problem relates to the inability to evacuate all airbubbles or pockets from the root canal during placement of the guttapercha points and associated pastes or resins. As the gutta percha pointcoated with pastes or resins is packed into the root canal, or assealers are worked in with a lentalo applicator, upper portions of thegutta percha or sealer can seal against the root canal wall, thustrapping air between the coronal portion and the root canal apex.Failure to remove such air pockets creates an area where subsequentinfection can fester. Although gutta percha is highly radiopaque, evenif the dentist can observe whether or not the root canal spaces havebeen adequately filled, the task of removing the packed materials andrepeating the procedure is time consuming, expensive, and uncomfortablefor the patient. Moreover, many sealer pastes are only moderatelyradiopaque and include silver powder, which makes the root canal toodark.

Lateral condensation using gutta percha is typically not sufficient toforce the highly viscous pastes, gutta percha, or resins into thelateral canals. Merely pushing against the top portion of the guttapercha does not exert very much force on the flowable pastes or resins,since pressurized fluids can escape around the space between the guttapercha, lateral condensation instrument, and the root canal rather thanbeing forced into the lateral canals or other areas occupied by airbubbles or pockets.

Finally, in the case where nonpolymerizable pastes, such as zincoxide/eugenol are used, the chemistries of such materials can interferewith the ability of subsequently placed prosthetic filling materials tochemically bond or adhere to the tooth.

In short, it would be an improvement of the art of endodontic proceduresto provide compositions and methods which improved the ability of anendodontic sealing material to penetrate, wet, adhere and seal to thedental tissues surrounding or defining the root canals.

It would be an additional improvement in the art to provide compositionsand methods that provided for a more thorough evacuation of air bubblesor air pockets within the root canal, as well as including lateralspaces or canals connected to or in communication with the main rootcanal branches.

It would also be an improvement in the art to provide compositions andmethods which yielded a filled root canal in which the sealing materialdid not interfere with the ability of a subsequently placed compositeresin material to bond or adhere to the tooth.

It would be a further advancement in the art if such compositions andmethods provided for the ability to allow for variable curing times suchas faster or slower curing, to account for variations in difficulty andsuccess that may be experienced by a dental practitioner.

It would yet be an improvement in the art if such compositions couldalso be light cured so as to reduce the time a patient must wait untilthe root canal sealing material was sufficiently cured to permitsubsequent filling of the remainder of the tooth with a compositefilling material.

Such compositions and methods for more effectively filling and sealing aroot canal and providing a bonding surface are disclosed and claimedherein.

SUMMARY OF THE INVENTION

The present invention encompasses adhesive resins for use in fillingand/or sealing a root canal during an endodontic procedure, as well asprocedures that employ such compositions. The adhesive sealing andfilling resins according to the present invention include a componentthat is compatible with a hydrophilic environment and that allows theresin to wet, penetrate and adhere to the dental tissue surrounding theroot canal. In addition, such resins are better able to penetrate intoand seal the lateral canals that often extend from the main root canalbranches. In order to assist such sealing, improved methods for applyinga pressure to the sealing and filling resins are also disclosed.

The adhesive sealing and filling compositions of the present inventioninclude one or more polymerizable acrylate or methacrylate monomers,oligomers or other prepolymers, preferably substituted with ahydrophilic constituent for better adhesion, a radio opacifying agent,and one or more types of polymerization initiators. The composition mayalso include other additives such as diluent or complementary monomers,oligomers, or prepolymers, fillers, antimicrobial agents, plasticizers,solvents and the like.

An example of an adhesive methacrylate resin substituted with ahydrophilic group (e.g., an oxyphosphorus group) is bis-glycidyldimethacrylate phosphate. In the alternative, the hydrophilic group mayinclude one or more of an oxysulfur group, a borate group, a carboxylgroup, a nitro group or a cyano group. An example of a radio opacifyingagent according to the present invention is bismuth chloride. An exampleof a suitable diluent monomer is urethane dimethacrylate. Examples ofpolymerization initiators include chemical initiators, such as peroxidesand amines, and photoinitiators, such as camphor quinone. Because it istypically impossible to completely cure a polymerizable resin usingphoto initiation as the sole means to initiate polymerization,particularly all the way down to the apex of the root canal, it willtypically be advantageous to include a chemical initiator so as toensure complete curing of the polymerizable resin(s) over time.

In a preferred embodiment, the chemical initiator will be selected andincluded in an amount so as to provide sufficient time for a dentalpractitioner to properly place the composition within the root canal andensure good penetration into the lateral canals. In most cases, it willbe advantageous to include a chemical curing agent that causes thepolymerizable resin to cure within a time period of from about 2 minutesto about 2 hours, more preferably from about 5 minutes to about onehour, and most preferably from about 10 minutes to about 30 minutes.

In the event that the dentist determines that the endodontic sealingresin has been properly placed, the dentist can optionally rapidly curethe upper portion of the resin by means of the inclusion of aphotoinitiator and the application of curing radiation, such as lightgenerated by a conventional dental curing lamp. In this way, the dentistcan cure the top few millimeters of endodontic sealing resin by means ofthe curing lamp so as to provide a hardened upper surface to which acomposite filling material can be chemically bonded or adhered. Thisgreatly speeds up the time in which a dentist can complete theendodontic procedure, although the procedure can be adequately performedusing a chemical initiator alone without a photoinhibitor.

Embodiments that include “dual cure” compositions (i.e., compositionsthat are capable of both chemical and light cure) provide some advantageover single cure resins. The rate of chemical curing can be adjusted toprovide an aforementioned window of time to account for variations inprocedure difficulty and success, while the light cure propertiesprovide for almost immediate curing of the top layer by photoinitiatedcuring once it has been determined that the sealing or filling materialhas been properly placed. This provides a tremendous advantage for boththe dentist and the patient because it obviates the need for a patientto either sit in the dental chair wasting time while the resin cures orelse having to make a return visit to receive the final fillingmaterial. Another advantage is that the duration of chemical curing isrelatively short compared to conventional sealers, thus minimizing thetendency of the composition constituents to leach into the surroundingtissue.

In another aspect of the invention, the adhesive resins are placedwithin the root canal by means of a narrow cannula or syringe tip deviceattached to a high pressure hydraulic device or system. Due to theviscosity of the mixed polymerizable resins or non resinous pastes suchas zinc oxide pastes, coupled with the small size of typical rootcanals, it is difficult to express sealing resins or pastes throughcannulas or syringe tips capable of entering into a root canal. For thisreason, the inventive methods according to the present inventioncontemplate the use of high pressure syringes or other hydraulicdevices, such as those disclosed in copending U.S. application Ser. No.09/467,419, filed Dec. 20, 1999, and presently assigned to UltradentProducts, Inc. For purposes of disclosure, the foregoing U.S. patentapplication is incorporated herein by specific reference.

In a preferred method for placing adhesive resins within a root canal,the apex of the root canal is first sealed using a gutta percha cone. Inorder to ensure that the apex has been adequately sealed, a “tug back”seal is formed. That is, the gutta percha cone is first inserted andthen removed. If it can be removed with little or no force, the guttapercha point is trimmed to yield a larger diameter tip and reinsertedinto the apex. This process is repeated until there is “tug back,” thusindicating that the fit between the gutta percha point and the apex issufficiently tight to adequately seal the apex and prevent flow ofsealing or filling material therethrough into the surrounding bonetissue.

After sealing the apex, the sealing or filling resin is inserted intothe root canal using a narrow cannula tip. The cannula tip is placedwithin the root canal near the apex and slowly raised as the root canalis filled with resin, thus minimizing or eliminating the formation ofair pockets or bubbles as the sealing or filling resin is progressivelyplaced within the root canal. This procedure greatly improves theability of the resin to initially purge most or all of the air fromwithin the root canal compared to simply dipping a gutta percha point inthe resin and stuffing the point into the root canal, or spinning thematerial with lentalo applicators, as is typically done usingconventional methods.

In order to further ensure that the endodontic sealing resin penetratesand seals every space, irregularity, or lateral canal of the root canal,it may be advantageous to apply pressure to the resin after it has beeninitially placed within the root canal. This may be accomplished, forexample, by inserting a plunger of complimentary size into the holepreviously bored through the crown of the tooth. The plunger willtypically include a plunger rod and a resilient plunger plug, such as aplug made of gutta percha material. In a preferred method for forming aplunger, excess gutta percha material trimmed from a gutta percha coneused to fill a root canal is wrapped around the end of a stiff metallicwire or plunger rod. The wire and gutta percha are then placed throughthe hole of the tooth. The wire is heated, which momentarily causes thegutta percha to melt and coalesce together, thus forming a resilientplunger plug having a size complementary to the hole in the tooth.

Inward pressure of the plunger from the crown toward the apex of theroot canal exerts pressure on the resinous sealing material, thusforcing the material into the cracks, crevices and lateral canals of theroot canal. Because the resilient gutta percha plug seals against thewalls defining the hole through the crown of the tooth, the resinousmaterial is not able to squeeze out between the tooth and the guttapercha plug but is instead forced into the aforementioned spaces,crevices or canals. In this manner, the resinous sealing or fillingmaterial is able to substantially form a hermetic seal of the rootcanal.

Providing a more complete seal of the loot canal greatly increases theability of the sealed root canal to resist the ingress of fluids intothe root canal. Such fluids, if allowed to enter a root canal, mayintroduce microbes capable of infecting the tooth and surrounding bone.In improving the ability of the resinous sealing material to actuallyseal the root canal, including lateral canals and other crevicestypically hard to fill, the inventive compositions and methods provide atremendous advantage over conventional compositions and methods inyielding a tooth that is more resistant to microbial leakage.

In view of the foregoing, one aspect of the invention is to providecompositions and methods which improve the ability of an endodonticsealing material to wet, adhere and seal to the dental tissuesurrounding or defining the root canals.

Another aspect of the invention is to provide compositions and methodsthat provide for a more thorough evacuation of air bubbles or airpockets within the root canal, as well as lateral spaces or canalsconnected to, or in communication with, the main root canal branches.

A further aspect of the invention is to provide compositions and methodswhich yield a filled root canal having a material to which a subsequentcomposite resin material can chemically bond or adhere.

Additional features and advantages of the invention will be set forth inthe description which follows, and in part will be obvious from thedescription, or may be learned by the practice of the invention. Thefeatures and advantages of the invention may be realized and obtained bymeans of the instruments and combinations particularly pointed out inthe appended claims. These and other features of the present inventionwill become more fully apparent from the following description andappended claims, or may be learned by the practice of the invention asset forth hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to describe the manner in which the above-recited and otheradvantages and features of the invention can be obtained, a moreparticular description of the invention briefly described above will berendered by reference to specific embodiments thereof which areillustrated in the appended drawings. Understanding that these drawingsdepict only typical embodiments of the invention and are not thereforeto be considered to be limiting of its scope, the invention will bedescribed and explained with additional specificity and detail throughthe use of the accompanying drawings, in which:

FIG. 1 is a cross sectional view of a tooth showing a root canal with agutta percha cone inserted into the apex so as to seal the apex andprovide a fluid-tight seal;

FIG. 2 is a cross sectional view of the tooth of FIG. 1 in which a smalldiameter cannula device has been inserted within the root canal for thepurpose of filling the root canal with an endodontic sealing or fillingresin;

FIG. 3 is a cross sectional view of the tooth of FIGS. 1 and 2 after theroot canal has been filled with an endodontic sealing or filling resin;

FIG. 4A is a cross sectional view of the tooth of FIG. 3 in which aportion of a gutta percha cone has been wrapped around the end of a wirepreparatory to heating and melting the gutta percha to form asyringe-like plunger to be inserted into the tooth;

FIG. 4B is a cross section view of the tooth of FIG. 4A in which thegutta percha has been melted and conformed to the diameter of theopening in the tooth so as to form a plunger-like device used to exertpressure onto the endodontic sealing or filling resin to force the resininto the lateral microfissures in communication with the root canal; and

FIG. 5 is a cross section view of a tooth in which the endodonticsealing or filling resin within the root canal is being partially curedusing a curing lamp preparatory to placing a final filling materialand/or crown to seal the root canal.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS I. Introduction

The present invention is directed to polymerizable resins used to fill aroot canal during endodontic procedures. The invention also related toimproved procedures for placing the inventive sealing or filling resins,as well as conventional resins or pastes, within a root canal. Toprovide better compatibility with the hydrophilic environment within atooth, the adhesive sealing or filling resins advantageously include acomponent that is compatible with hydrophilic and mineralized dentaltissues. Increased hydrophilic compatibility facilitates wetting of thedental tissue, enables penetration of the sealing material within gaps,spaces and lateral canals associated with the root canal, and promotespenetration into the dentinal tubules and, hence, superior adhesion tothe dental tissue surrounding the root canal.

Sealing or filling resins and other flowable sealing or fillingmaterials may optionally be placed within a root canal by means ofpressurized hydraulic systems or devices able to deliver viscous fluidsthrough narrow cannulas placed within the root canal. Once placed, thesealing resins or other materials are advantageously forced underpressure into the lateral canals associated with the main root canalbranches, thus providing a much better seal of the root canal. This maybe accomplished by means of a mini syringe-like plunger or like devicethat works in conjunction with a customized bore through the crown ofthe tooth.

The adhesive sealing or filling resins within the scope presentinvention typically include one or more monomers, oligomers or otherprepolymers that promote adhesion, such as acrylate or methacrylatemonomers, oligomers, or prepolymers substituted with a hydrophilicconstituent, a radio opacifying agent, and one or more types ofpolymerization initiators. The term “radiopaque” refers to materialsthat allow the composition to be more easily seen using an X-ray. Thecomposition may also include other additives such as diluent monomers,oligomers, or other prepolymers, fillers, antimicrobial agents,plasticizers, solvents and the like.

The terms “alkyl acrylate” and “alkyl methacrylate”, unless otherwisespecified, shall refer to monomers, oligomers, and other prepolymersthereof (e.g., copolymers).

The compositions and methods are effective in reliably sealing the rootcanal from the ingress of fluids and bacteria from the crown and/orperiodontal tissue. This helps to ensure the mechanical integrity of thetreated tooth. Equally or more important, it protects surrounding bonefrom being infected by bacteria that may have otherwise infected thetreated tooth. In one embodiment, the sealing or filling resins may bedual curable, that is, curable both chemically and by irradiation withlight energy. This gives the dentist greater control over the time ittakes to provide sufficient curing of the sealing or filling resin topermit placement of a final filling material or prosthetic covering.

II. Endodontic Sealing or Filling Compositions

A wide variety of polymerizable resins, radiopaque materials,initiators, and other components may be used within the inventiveendodontic sealing or filling compositions within the scope of theinvention, including those disclosed in U.S. Pat. No. 6,071,528 toJensen and copending U.S. application Ser. No. 09/736,729, filed Dec.14, 2000, both of which are assigned to Ultradent Products, Inc., SouthJordan, Utah. For purposes of disclosure, the foregoing patent andapplication are incorporated by reference.

The compositions within the scope of the invention can be chemicallycurable, photo curable, or dual cure. In the case of chemical and dualcure sealing or filling compositions it will typically be necessary toprovide a two-part (or multi-part) composition that is mixed by thedentist just prior to use. One part may advantageously include all theconstituents of the resin sealing or filling together with one half ofthe chemical cure system (e.g., a peroxide compound), while another partwill advantageously include all the constituents of the resin sealingwith the other half of the chemical cure system (e.g., an aminocompound). In the case of a photocured sealing or filling composition,the polymerizable resin will advantageously be stable in the presence ofthe photoinitiator absent the application of radiant energy.

In the case of chemically cured systems, the final endodontic sealing orfilling composition, upon mixing the multiple parts together, willpreferably cure within a time period of about 2 minutes to about 2hours, more preferably in a range of about 5 minutes to about 1 hour,and most preferably in a range of about 10 minutes to about 30 minutes.

On the other hand, in the case of a photo cured system, including dualcure systems, irradiating the sealing or filling composition withradiant energy, such as from a ultraviolet curing lamp, can effect muchmore rapid curing than chemical cure alone. The upper 1-3 mm of sealingor filling material within the root canal can typically be photo curedin a period of time of from about 10 seconds to about one minute.

A. Polymerizable Adhesive and Diluent Resins.

The polymerizable sealing or filling compositions according to theinvention include at least one polymerizable adhesive resin that is atleast partially hydrophilic and/or includes constituents which make anotherwise hydrophobic resin more adhesive to dental tissue. Thepolymerizable adhesive resins within the scope of the invention mayinclude any monomer, oligomer or prepolymer that yields a compositionthat is capable of wetting and penetrating into the dentinal tubules.General, examples include a wide range of acrylates, methacrylates,alkylhydroxy methacrylates, alkylamino methacrylates, and derivativesthereof. More specific examples of polymerizable adhesive resins includeglycidyl dimethacrylate, 2-hydroxy ethyl methacrylate, 3-hydroxy propylmethacrylate, 4-hydroxy butyl methacrylate, triethylene glycoldimethacrylate, and polyethylene glycol dimethacrylate.

In preferred embodiments, the adhesion monomer include one or more alkylacrylates or alkyl methacrylates that have been substituted with atleast one additional hydrophilic group in addition to the acrylateand/or methacrylate ester linkage. In a preferred embodiment, theadditional hydrophilic group includes an oxyphosphorus group, such thatpreferred polymerizable adhesive resins include one or more ofoxyphosphorus alkyl acrylates and oxyphosphorus alkyl methacrylates, anexample of which is bis glycerol dimethacrylate phosphate. Examples ofother oxyphosphorus alkyl methacrylates within the scope of theinvention include bis 2-hydroxy ethyl methacrylate phosphate, phosphateester of p-hydroxyphenyl methacrylamide, phosphate ester of 3-hydroxypropyl methacrylate, and phosphate ester of 4-hydroxy butylmethacrylate.

Notwithstanding the foregoing examples, the oxyphosphorus alkylacrylates and alkyl methacrylates can be any alkyl acrylate or alkylmethacrylate having an oxyphosphorus group selected from the groupconsisting of:

-   -   wherein R comprises an alkyl or aryl radical.

The oxyphosphorus group not only tends to increase the adhesiveness ofthe resin compared to analogous compounds lacking this addedconstituent, but it also increases the water solubility andhydrophilicity, of the resulting resin. In an informal comparison of therelative water solubilities of glycidyl dimethacrylate and bis glyceroldimethacrylate phosphate, the latter was found to be considerably morewater soluble compared to the former. On this basis, it was presumedthat the addition of the oxyphosphorus group increased thehydrophilicity of the resulting compound compared to the originalcompound.

Examples of other hydrophilic groups include oxysulfur groups, boricacid derivatives, carboxylic acid and carboxylic acid derivatives, aminogroups, nitro groups, and cyano groups. The term “oxysulfur” shall referto hydrophilic groups containing sulfur that can be substituted on toalkyl acrylate and alkyl methacrylate resins, including sulfoxides,sulfonic acid, sulfonates, sulfinic acid, sulfinates, and sulphates.Oxysulfur groups (or radicals) generally have a formula selected fromthe group consisting of:

-   -   wherein R comprises a hydroxyl, alkyl, or alkoxy radical.

Boric acid derivatives (or borates) generally have the formula:

-   -   wherein R₁ and R₂ may variously comprises a hydrogen or alkyl        radical.

Carboxylic acid and carboxylic acid, derivatives (e.g., esters andamides) (together “carboxyl radicals” or “groups”) generally have theformula:

-   -   wherein R comprises a hydroxyl, alkoxy, or amino radical.

Amino radicals generally have the formula:

wherein R₁ and R₂ may variously comprises a hydrogen or alkyl radical.

Nitro groups are generally designed as —NO₂.

Cyano groups include cyanide (—CN), isocyanide (—NC), cyanate (—CNO) andisocyanate (—NCO) radicals. Because the cyanide and isocyanide radicalsin organo cyanide compounds (i.e., nitrites and isonitriles) are notnubile, such compounds do not possess the same level of toxicity ascyanide salts and hydrogen cyanide gas. Moreover, in light of therelatively fast curing times, there is little risk that dangerousmonomers of any kind will diffuse into the body.

In addition to the adhesive resin, the compositions according to theinvention may include one or more additional (or diluent) resins toachieve the desired properties of initial flowability, curability, andfinal cured strength and hardness. In the case where the adhesive resinincludes an alkyl acrylate or alkyl methacrylate substituted with anadditional hydrophilic group, the diluent resin may include one or morenon substituted alkyl acrylate or alkyl methacrylates. In addition,resins that are more hydrophobic and yet are suitable as diluent resinsinclude urethane dimethacrylate, p-hydroxyphenyl methacrylamide,butanediol dimethacrylate, and bisphenol-A-diglycidyl dimethacrylate(“Bis-GMA”).

The adhesion resins are preferably included in a concentration rangingfrom about 0.01% to about 90% by weight of the composition, morepreferably from about 0.5% to about 30% by weight, and most preferablyfrom about 1% to about 10% by weight of the composition.

The diluent resins may be included in amounts of up to about 95% byweight of the composition, preferably in a range from about 5% to about80%, and more preferably in a range from about 10% to about 70% byweight of the composition.

B. Initiators.

Initiators are provided in the composition to induce polymerization ofthe monomer, oligomer, or other prepolymers within the sealing andfilling compositions. The initiators or curing agents may includeradiant energy polymerization initiators with or without an appropriateorganic amine additive or a chemical initiator with an appropriateorganic amine additive.

1. Photoinitiators.

Examples of photoinitiators within the scope of the invention include,but are not limited to, x-diketones, camphor quinone, benzoin methylether, 2-hydroxy-2-methyl-1-phenyl-1-propanone, diphenyl2,4,6-trimethylbenzoyl phosphine oxide, benzoin ethyl ether,benzophenone, 9,10-anthraquinone, and derivatives thereof. Thephotoinitiators can be used with or without tertiary amines. Thephotoinitiator provides for photo-initiated polymerization of at leastabout the upper 1-3 mm of the sealing and filling composition in aperiod of time about 10 seconds to about 1 minute.

Photoinitiators are preferably included in an amount in a range fromabout 0.05% to about 5% by weight of the composition, more preferably ina range from about 0.1% to about 2% by weight, and most preferably in arange from about 0.2% to about 1% by weight of the composition.

2. Chemical Initiators.

Examples of chemical initiators include a wide range of peroxides, otherper components, and other free radical generators. A two-part chemicalcuring system typically includes a peroxide constituent in one part andan amino compound in another. Exemplary peroxides include, but are notlimited to, benzoyl peroxide, 2-butanone peroxide, lauroyl peroxide,t-butyl peroxide, t-butyl peroctoate, potassium persulfate, sodiumperborate, isopropyl percarbonate, cumene hydroperoxide, dicumylperoxide, 2,4-dichlorobenzoyl peroxide, diisopropylbenzenemonohydroperoxide, and ammonium persulfate.

Examples of amino compounds include, but are not limited to,dimethylamino ethylmethacrylate, triethylamine, 2-dimethylamino ethanol,diethylamino ethylmethacrylate, trihexylamine, N,N-dimethyl-p-toluidine,dimethyl-p-toluidine, N,N-dimethyl aniline, ferric ethylenedinitrilotetraacetate, polyethylene polyamines, N-methylethanolamine,2,2′(p-tolyimino) diethanol, and derivatives thereof.

In a preferred embodiment, the chemical initiator will be selected andincluded in an amount so as to provide sufficient time to allow thedentist or dental practitioner to have sufficient time to place theresinous sealing or filling material into the root canal and cause it toflow into the lateral canals. In other words, once mixed, the curingtime will be sufficiently long so as to allow the dentist to carry out adesired sealing and/or filling procedure. On the other hand, unlikeconventional sealers, which often cure very slowly, sometimes over aperiod of one or more days, the sealing and filling materials of theinvention are typically formulated so that they will cure more rapidly,typically in 2 hours or less in order to inhibit or avoid leaching ofthe polymerizable monomer into the surrounding dental tissue.

In most cases, it will be advantageous to include a chemical curingagent in order for the polymerizable resin to cure within a time periodof about 2 minutes to about 2 hours, more preferably from about 5minutes to about 1 hour, and most preferably from about 10 minutes toabout 30 minutes. In some cases, it may be desirable to allow sufficienttime to determine whether or not the sealing material has been properlyplaced. If not, the uncured resin can be removed and replaced with newresin in a follow-up procedure.

Chemical initiators are preferably included in an amount in a range fromabout 0.01% to about 5% by weight of the composition, more preferably ina range from about 0.05% to about 2% by weight, and most preferably in arange from about 0.1% to about 1% by weight of the composition.

C. Radiopaque Fillers.

Radiopaque fillers are advantageously included in order to provide theability of the dentist to X-ray and determine how well the endodonticresin has penetrated into and filled the root canal, including thelateral canals. Examples of fillers that can provide increased radioopacity include bismuth salts such as bismuth chloride, silver andsilver salts such as silver chloride, barium salts such as bariumsulfate or barium chloride, tungsten salts, titanium dioxide, andstrontium salts such as strontium sulfate and strontium chloride. Theseand other fillers such as silicon dioxide and calcium phosphate tribasicmay also be used to minimize polymerization shrinkage and the total heatpotential of polymerization.

It is within the scope of the invention to include fillers in an amountof up to about 85% by weight of the composition, more preferably in arange from about 2% to about 70% by weight, and most preferably in arange from about 5% to about 50% by weight of the composition.

D. Antimicrobial Agents.

The sealing or filling compositions may optionally include one or moreantimicrobial agents to assist in cleansing and sterilizing the rootcanal and to prevent later infection. Examples of suitable antibacterialagents include organohalogens, antibiotics, alkali metal oxides,hydroxides and carbonates, and alkaline earth metal oxides, hydroxidesand carbonates.

Examples of antibacterial organohalogens include 1,1′-hexamethylenebis(5(p-chlorophenyl)biguanide), cetyl pyridinium chloride, benzalkoniumchloride, and cetyl pyridinium bromide.

Examples of suitable antibiotics include: 4′-sulfamoylsulfanilanilide,3-amino-6-(2-(5-nitro-2-furyl)vinyl)pyridazine, trans-pseudomonic acid,xanthomycin, alpha-amino-p-toluene sulfonamide, alpha-azido benzylpenicillin, penicillin O, penicillin N, monopropionyl erthromycin, anderythromycin 9(O-((2-methoxy ethoxy)methyl) oxime.

Examples of suitable alkali metal hydroxides include sodium hydroxideand lithium hydroxide.

Examples of suitable alkaline earth metal oxides include calcium oxide,magnesium oxide, barium oxide, and strontium oxide.

Examples of suitable alkaline earth metal hydroxides include calciumhydroxide, magnesium hydroxide, barium hydroxide, and strontiumhydroxide.

A more preferred antimicrobial agent is calcium hydroxide since calciumhydroxide not only kills microorganisms but is chemically compatiblewith dental tissue. The antimicrobial agent is preferably included in anamount in a range from about 0.001% to about 30% by weight of thecomposition, more preferably in a range from about 0.005% to about 10%by weight, and most preferably in a range from about 0.01% to about 5%by weight of the composition.

E. Other Additives.

It is certainly within the scope of the invention to include otheradditives or adjuvents as desired in order to impart a desired property,such as less or non radiopaque fillers, solvents, dyes or plasticizers.For example, silica may be included in order to impart hardness in thecase where a sealing filler material is desired. Keeping the silicacontent low, however, improves the ability to later drill out a portionof the cured material if desired, such as to place a post during a crownrestoration.

Polymerization inhibitors are often added to polymerizable resins at thetime of manufacture to inhibit or prevent premature polymerization. Ifso, the raw polymerizable materials used in manufacturing dental bondingcomposition according to the invention may include one or morepolymerization inhibitors. An example of a polymerization inhibitor ishydroquinone. Of course, it is also within the scope of the invention todeliberately add a polymerization inhibitor to the sealing and fillingcompositions according to the invention in order to prevent prematurepolymerization and curing.

III. Methods for Sealing Root Canal with Endodontic Resins

An exemplary method for placing and then curing an endodontic sealing orfilling resin within a root canal is illustrated in FIGS. 1-5. FIG. 1depicts a tooth 10 that has been subjected to a root canal procedure.The tooth 10 includes a pair of root canals 12, each of which terminatesat an apex 14 that extends through the bottom of the root 16. An opening18 through the crown of the tooth provides access to the root canals 12,thereby permitting endodontic tools (not shown) to be inserted into theroot canals 12. A gutta percha cone 20 has been inserted into eachopening 18 in order to seal the apex 14 of each root canal 12 to preventflow of sealing material into the surrounding bone tissue.

In order to ensure that the gutta percha cone 20 forms a reliable sealwithin the apex 14, a procedure involving “tug back” is preferablyperformed. In this procedure, the gutta percha cone is inserted andremoved, sometimes more than one time, to determine how much force isneeded to remove the gutta percha cone. If it can be removed with littleor no force, there is insufficient tug back, and the gutta percha pointis trimmed to yield a larger diameter tip and reinserted into the apex.This process is repeated until there is sufficient tug back, orresistance, felt by the dentist or dental practitioner. One of ordinaryskill in the art of endodontics will know when there is sufficient tugback to confirm an adequate seal of the apex 14 by the gutta percha cone20. Sufficient tug back indicates that the fit between the gutta perchacone and the apex is sufficiently tight to adequately seal the apex andprevent flow of sealing or filling material therethrough into thesurrounding bone tissue.

In addition to the root canals 12, lateral canals 22 extend from theroot canals 12 and provide communication between the root canals 12 andthe surrounding periodontal tissue of the lower portion of the tooth 10.The lateral canals 22 are particularly difficult to seal usingconventional compositions and methods. The inventive compositions andmethods, however, facilitate penetration of resinous sealing or fillingmaterial into the lateral canals 22.

In a preferred method for placing a resinous sealing or filling materialwithin a root canal, FIG. 2 depicts a syringe tip 24 having a narrowdiameter cannula 26 attached to an enlarged portion 28 of the syringetip 24 used to insert sealing or filling material into the root canal12. Due to the narrow opening of the cannula 26, and; because typicalsealing or filling materials often sufficiently viscous that they maynot readily pass through the cannula 26, it will generally beadvantageous for the syringe tip 24 to be attached to a high pressurehydraulic injection system (not shown). An example of high pressurehydraulic syringes or systems are set forth in the aforementionedcopending U.S. application Ser. No. 09/467,419, filed Dec. 20, 1999.Examples of narrow cannulas sized for entry into a root canal are setforth in U.S. Pat. No. 6,079,979, which is assigned to UltradentProducts, Inc. For purposes of disclosing hydraulic pressurizing systemsand cannulas sized to fit within a root canal, the foregoing patentapplication and patent are incorporated herein by specific reference.

The tip of the cannula 26 is initially placed within the root canal 12near the apex 14, and sealing or filling material (not shown) isexpressed therefrom into the root canal 12. As the resinous materialbegins and continues to fill up the root canal 12, the cannula 26 isslowly raised or withdrawn from the root canal 12. This manner offilling the root canal 12 with resinous material minimizes or eliminatesthe formation of air pockets or bubbles as the resin is progressivelyplaced within the root canal 12. This procedure greatly improves theability of the resin to initially purge most or all of the air fromwithin the root canal 12 compared to simply dipping a gutta percha pointin the resin and stuffing the point into a root canal, as isconventionally done.

FIG. 3 depicts a tooth 10 into which a resinous sealing or fillingmaterial 30 has been successfully placed within the root canals 12, withlittle or no formation of air; pockets. Even so, initial placement ofthe resin 30 in this manner does not typically result in completefilling of the lateral canals 22. To ensure that the endodontic sealingor filling material 30 has penetrated into and sealed every space,irregularity or lateral canal 22 of the root canal 12, it may beadvantageous to apply additional pressure to the resin 30 after it hasbeen initially placed within the root canals 12. In one embodiment,additional pressure may be applied by inserting a plunger-like deviceinto a hole 32 through the crown 33 of the tooth 10 that is initiallymade to provide access to the root canals 12 during the root canalprocedure. FIGS. 4A and 4B illustrate this optional procedure.

In order for the plunger-like device to work in applying sufficientpressure so that the filling or sealing resin 30 is forced into thelateral canals 22, it will be advantageous to provide a resilientplug-like material that is able to conform to and seal against the innerwall 34 of the tooth 10 defining the hole 32. The resilient plug-likematerial will preferably have a diameter that is complementary to thediameter of the hole 32. Although the plunger-like device may includeany resilient plug-like material, in a presently preferred method, theresilient plug-like material is formed from excess gutta percha materialthat is trimmed off of the gutta percha cone 20.

As more clearly depicted in FIG. 4A, a length of excess gutta percha iswrapped around a wire 36 to form a gutta percha wrap or bundle 38 toform a plunger 40. Heat is then applied to the wire 36 in order to causethe gutta percha wrap or bundle 38 to melt slightly so that it coalescestogether to form the resilient plug-like material. While the guttapercha bundle 38 is in a plastic state, the plunger 40 is placed intothe hole 32 of the tooth 10 in order to allow the gutta percha bundle toflow or otherwise conform to the size and shape of the hole 32.

As shown in FIG. 4B, once the gutta percha bundle 38 has coalescedtogether and conformed to the shape of the hole 32, it yields a plunger40 having a gutta percha plug 42 on the end thereof. The gutta perchaplug 42 is allowed to cool and thereby adhere to the wire 36.Thereafter, the wire 36 and gutta percha plug 42 yield a plunger 40 thatcan be used to exert pressure on the resinous sealing or fillingmaterial 30 in order to force it to flow into the cracks, crevices andlateral canals 22 that may extend from the root canal 12. In addition,pressure applied by the plunger 40 may also assist the resin 30 to flowinto the dentinal tubules in order to promote better adhesion betweenthe resin 30 and the dental tissue surrounding the root canal 12.

As depicted in FIG. 4B, force applied to the plunger 40 in a directionfrom the crown of the tooth 10 towards the apex 14 of the root canals12. Force may be applied to the plunger 40 manually or by means ofpliers or other gripping tools. Pressure is maintained on the resinoussealing or filling material 30 because the elastomeric plug 42 sealsagainst the inner wall 34 defining the hole 32 through the crown 33 ofthe tooth 10. Because of this, the resinous material 30 is not able tosqueeze out in appreciable amounts between the tooth wall 34 and theresilient plug 42. Instead, the pressure exerted onto the resinousmaterial 30 forces it into the aforementioned spaces, crevices orcanals. In this manner, the resinous sealing material 30 is able to forma substantially hermetic seal of the root canals 12.

Although FIGS. 4A and 4B depict a preferred method for forming asuitable plunger 40 for use in applying pressure to the resinous sealingor filling material 30, it should be understood that plunger-likedevices or other pressurizing means would be within the scope of theinvention. In view of the present disclosure, one of ordinary skillcould design other pressuring means that would work to apply pressure tothe resin 30. For example, in place of gutta percha, the plunger 42 maycomprise any resilient or elastomeric material that can seal against theinner wall of the hole 32 through the crown. Examples include othernatural rubbers, silicone rubbers and other synthetic rubbers orelastomers.

Providing a more complete seal of the root canal 12 greatly increasesthe ability of the sealed root canals 12 to resist the ingress of fluidstherein. Such fluids may enter the root canals 12, for example, throughfissures in the crown and/or periodontal tissue. Such fluids, if allowedto enter the root canals 12, may carry microbes capable of attacking anddecaying the dental tissue surrounding the root canals 12, thuscompromising the mechanical integrity of the dead tooth 10 and, moreimportantly, potentially infecting surrounding teeth. In improving theability of the resinous material 30 to more effectively seal the rootcanals 12, including the lateral canals 22 and other crevices that aretypically hard to fill, the inventive compositions and methods provide atremendous advantage over conventional compositions and methods inyielding a tooth that is more resistant to microbial attack.

As set forth above, the resinous sealing or filling materials may bechemically cured, photo cured or dual cured. In a preferred embodiment,the compositions will be dual cured. That is, they will preferably becured both by means of a chemical curing agent and by the application ofradiant energy. Because photo curing is only capable of curing the toplayers of the resinous sealing or filling material 30, but is incapableof sealing all the way down to the apex 14 of the root canal 12, photocuring alone is typically insufficient to provide an adequately curedresinous material 30 throughout the entire length of the root canal 12.For this reason, it will typically be necessary to provide chemicalcuring of the resinous material 30 in order to ensure that resinousmaterial cures completely throughout the entire root canal 12 andassociate lateral canals 22, crevices and spaces.

Nevertheless, because chemically cured sealing or filling materialspreferably cure slowly over time (e.g., between 20 minutes and 2 hours)so as to provide the dentist with adequate time to mix and then placethe sealing or filling material, it may be desirable to speed up thecuring process once proper placement of the resinous sealing materialhas been verified. Once a dentist or other dental practitioner issufficiently confident that the resinous material has been adequatelyplaced, it may be desirable to is speed up the curing process, at leaston the surface or upper portion 44 of the resinous material 30, in orderto provide a hardened surface 46 to which a composite material (notshown) can be bonded.

As depicted in FIG. 5, a curing lamp 50 that emits radiant energy 52,such as ultraviolet radiation, can be used to cure the top or upperportion 44 of a dual cure sealing or filling material. The photo curedportion 44 will typically only extend partially down the root canal 12while the remaining portion 48 will extend all the way to the apex 14 ofthe root canal. The hardened upper portion 44 of the resinous materialprovides a hardened surface 46 to which a composite filling material(not shown) can immediately be chemically bonded or adhered. This allowsthe dentist to rapidly complete the endodontic process and eliminatesthe need for the patient to either sit in the dental chair while theresinous material chemically cures or make a appointment for a follow upvisit to receive the final filling material.

It should be understood that the compositions and procedures accordingto the present invention may be used with or without gutta perchapoints. One advantage of using gutta percha points is that they can beused to seal the apex 14 with each root canal 12 prior to placing theresinous sealing material therein. This helps to prevent incursion ofthe sealing or filling material into the surround bone tissue. Anotheradvantage of a gutta percha point is that it provides a path throughwhich a hole can be drilled through the sealed root canal withoutcompromising the surrounding cured sealing or filling material. Suchholes are referred to as “channel holes” or “post channel holes”.Channel holes may be drilled, for example, in order to place reinforcingposts (not shown) down the root canal in the case of a relatively weaktooth. Posts are also used when attaching a prosthetic crown to a tooth.

On the other hand, the resinous sealing or filling materials accordingto the present invention will typically be softer than typical compositematerials and may be easily drilled in many cases. Because of this, itmay be unnecessary to utilize gutta percha points to facilitate theformation of channel holes through the root canal if needed.

Another advantage of the compositions and methods according to thepresent invention is that they provide a bonding surface to which acomposite material, such as materials that include Bis-GMA, can form achemical or adhesive bond. Prior art antiseptic pastes, such as zincoxide/eugenol or calcium hydroxide mixed with iodoform, do not provide abonding surface to which composites can bond. Such materials aregenerally inert and relatively soft, thus providing neither chemical normechanical bonding possibilities. Moreover, to the extent that suchmaterials become interposed between the composite material and thetooth, they may inhibit bonding between the composite material and thetooth. In the case of amalgam, providing a hardened sealing or fillingmaterial, at least on the surface of the sealed root canal, willfacilitate placement of the amalgam. Because of the soft nature of theprior antiseptic pastes, it was always necessary to utilize a post inorder to provide a mechanical attachment surface to which a composite oramalgam filling material could attach. The photocurable sealing orfilling materials according to the invention reduce or eliminate theneed for such posts.

The resinous sealing or filling materials according to the presentinvention are also safer compared to prior art sealers, such as 26H or26 Plus sold by Dentsply, which are known to leach formaldehyde into thesurrounding dental tissue.

IV. Examples of the Preferred Embodiments

Several examples of the present invention are presented as merelyillustrative of some embodiments of the present invention. Theseexamples are not to be construed as limiting the spirit and scope of theinvention. Examples written in past tense refer to actual compositionsthat have been made, while those in present tense are hypothetical innature, though based on mix designs that have already been made.

Example 1

A dual cure dental composition suitable as an endodontic sealing orfilling material was prepared in two parts, with each part having thefollowing components in the stated amounts:

Part 1 Triethylene Glycol Dimethacrylate 16.8% Benzoyl Peroxide  0.2%Diurethane Dimethacrylate 30.0% Bis glycerol dimethacrylate phosphate 5.0% Bismuth Chloride Oxide 40.0% Calcium Lactate Pentahydrate  6.0%Silicon Dioxide  2.0% Total Part 1:  100%

Part 2 Triethylene Glycol Dimethacrylate 16.8% p-Tolyimino Diethanol 0.2% Phenyl bis(2,4,6-trimethyl benzoyl)  0.5% Phosphine OxideDiurethane Dimethacrylate 30.0% Bis glycerol dimethacrylate phosphate 5.0% Bismuth Chloride Oxide 40.0% Calcium Lactate Pentahydrate  5.5%Silicon Dioxide  2.0% Total Part 2:  100%

The final composition was made by mixing equal amounts of Parts 1 and 2.Once mixed, the mixed composition was able to cure in less than 2 hours,thus preventing or inhibiting leaching of monomers and other materialsfrom the root canal into the surrounding dental tissues. The mixedcomposition was also capable of accelerated curing as a result ofirradiating the composition with radiant energy, such as by means of adental curing lamp.

Example 2

The dental composition of Example 1 is reformulated so as to be onlycapable of chemical cure.

Example 3

An adhesive antimicrobial dental composition was formed having thefollowing components and concentrations:

Percent by Weight Component of the Mixture calcium hydroxide 10.0%bis-glycerol methacrylate phosphate 5.0% urethane dimethacrylate 57.0%triethylene glycol dimethacrylate 6.0% titanium dioxide 1.0% calciumphosphate tribasic 10.0% dimethyl amino ethyl methacrylate 0.5%camphorquinone 0.2% barium sulfate 10.3%

Example 4

In this example, an adhesive antimicrobial dental composition is formedhaving the following composition:

Percent by Weight Component of the Mixture bis 2-hydroxy ethylmethacrylate 10.0% barium hydroxide 25.0% calcium phosphate tribasic5.0% benzoin ethyl ether 0.4% N-methylethanol amine 0.5% glyceroldimethacrylate 59.1%

Example 5

In this example, an adhesive antimicrobial dental composition is formedhaving the following composition:

Percent by Weight Component of the Mixture strontium oxide 30.0%camphorquinone 0.5% diethyl amino ethyl methacrylate 0.5% bis glycerylmethacrylate phosphate 69.0%

Example 6

In this example, an adhesive antimicrobial dental composition is formedhaving the following composition:

Percent by Weight Component of the Mixture cetyl pyridinium chloride4.0% strontium chloride 10.0% 2-hydroxy-2-methyl-1-phenyl-1-propanone0.5% diphenyl 2,4,6-trimethylbenzoyl phosphine oxide 0.5% xanthomycin1.0% phosphate ester of 4-hydroxy butyl methacrylate 29.0% butane dioldimethacrylate 55.0%

Example 7

In this example, an adhesive antimicrobial dental composition is formedhaving the following composition:

Percent by Weight Component of the Mixture penicillin N 3.5% silicondioxide fumed 16.0% bis-glyceryl methacrylate phosphate 3.0%benzophenone 1.0% tri hexyl amine 1.5% calcium phosphate tribasic 10.0%bis 2-hydroxy ethyl methacrylate 4.0% triethylene glycol dimethacrylate61.0%

Example 8

In this example, an adhesive antimicrobial dental composition is formedhaving the following composition:

Percent by Weight Component of the Mixture 4′-sulfamoylsulfanilanilide1.0% 1,1′-hexamethylene bis (5(p-chlorophenyl) 1.0% biguanide) phosphateester of 3-hydroxy propyl methacrylate 5.0% urethane dimethacrylate92.0% benzoin ethyl ether 1.0% 2-dimethylaminoethanol 1.0%

Example 9

In this example, an adhesive antimicrobial dental composition is formedhaving the following composition:

Percent by Weight Component of the Mixture magnesium oxide 15.0% bariumchloride 40.0% 9,10-anthraquinone 0.9% triethylamine 0.3% bis glycerylmethacrylate phosphate 43.8%

The present invention may be embodied in other specific forms withoutdeparting from its spirit or essential characteristics. The describedembodiments are to be considered in all respects only as illustrated andnot restrictive. The scope of the invention is, therefore, indicated bythe appended claims rather than by the foregoing description. Allchanges which come within the meaning and range of equivalency of theclaims are to be embraced within their scope.

1. A method for treating a tooth following or during an endodonticprocedure comprising: providing a tooth that includes an access holedrilled into and extending through the crown of the tooth, said accesshole providing access to at least one root canal of the tooth that hasbeen cleaned by an endodontic procedure; mixing together initiallyseparate parts of a multipart endodontic composition to form a mixedfilling and sealing composition which is initially flowable and suitablefor placement into a root canal during a root canal procedure and whichhardens over time, the mixed composition initially comprising: apolymerizable resin portion contained in at least one of the initiallyseparate parts and consisting essentially of a hydrophilic polymerizableadhesive resin that is at least one of a hydrophilic acrylate ormethacrylate capable of bonding to dental tissue found within a rootcanal and which includes one or more acrylate and/or methacrylate esterlinkages, wherein at least a portion of the at least one acrylate ormethacrylate is substituted with at least one hydrophilic group inaddition to the one or more acrylate and/or methacrylate ester linkages,wherein the at least one hydrophilic group comprises at least one of anoxysulfur radical, borate radical, carboxyl radical, or nitro radical;and a two-part chemical cure system comprised of: at least oneperoxide-based component contained in at least one of the initiallyseparate parts; and at least one amino component contained in at leastone other of the initially separate parts that does not contain theperoxide-based component; wherein the two-part chemical cure system,upon mixing the initially separate parts together, causes at least aportion of the polymerizable resin portion to polymerize over a periodof time; introducing the mixed composition into the at least one rootcanal of the tooth; allowing the mixed composition to at least partiallypolymerize and harden within the root canal; and filling the access holewith a filling material.
 2. A method as recited in claim 1, wherein thefilling material chemically bonds to an exposed portion of the mixedcomposition within the root canal.
 3. A method as recited in claim 1,wherein the mixed composition is introduced in to the root canal bymeans of a narrow diameter cannula sized to fit within the root canaland in fluid communication with a high pressure hydraulic system.
 4. Amethod as recited in claim 1, further including applying additionalpressure to the mixed composition after introducing it into the rootcanal.
 5. A method as recited in claim 4, wherein the application ofadditional pressure is carried out by means of inserting an elastomericplug into the access hole and applying force to the plug in order toexert fluid pressure onto the mixed composition, the elastomeric plugbeing sized so as to form a substantially fluid-tight seal between theplug and dental tissue surrounding the access hole.
 6. A method asrecited in claim 1, wherein the mixed composition hardens in a timeperiod of about 2 minutes to about 2 hours after mixing thepolymerizable resin portion and two-part chemical cure system together.7. A method as recited in claim 1, wherein the mixed composition hardensin a time period of about 5 minutes to about 1 hour after mixing thepolymerizable resin portion and two-part chemical cure system together.8. A method as recited in claim 1, wherein the mixed composition hardensin a time period of about 10 minutes to about 30 minutes after mixingthe polymerizable resin portion and two-part chemical cure systemtogether.
 9. A method as recited in claim 1, wherein the mixedcomposition further includes at least one polymerization photoinitiator,the method further comprising irradiating with radiant energy an exposedportion of the mixed composition within the root canal in order topolymerize and harden at least a portion of the mixed composition withina period of time of about 10 seconds to about 1 minute.
 10. A method asrecited in claim 9, wherein the polymerization photoinitiator comprisesat least one of camphor quinone, benzoin methyl ether,2-hydroxy-2-methyl-1-phenyl-1-propanone, diphenyl 2,4,6-trimethylbenzoylphosphine oxide, benzoin ethyl ether, benzophenone, or9,10-anthraquinone.
 11. A method as recited in claim 1, wherein theadhesive resin has an initial concentration in a range from about 0.01%to about 90% by weight of the mixed composition.
 12. A method as recitedin claim 1, wherein the adhesive resin has an initial concentration in arange from about 0.5% to about 30% by weight of the mixed composition.13. A method as recited in claim 1, wherein the adhesive resin has aninitial concentration in a range from about 1% to about 10% by weight ofthe mixed composition.
 14. A method as recited in claim 1, wherein theperoxide-based component comprises at least one of benzoyl peroxide,2-butanone peroxide, lauroyl peroxide, tert-butyl peroxide, t-butylperoctoate, potassium persulfate, sodium perborate, isopropylpercarbonate, cumene hydroperoxide, dicumyl peroxide,2,4-dichlorobenzoyl peroxide, diisopropyl benzene monohydroperoxide, orammonium persulfate.
 15. A method as recited in claim 1, wherein theamino component comprises at least one of dimethylamino ethylmethacrylate, triethyl amine, 2-dimethylamino ethanol, diethylaminoethyl methacrylate, trihexyl amine, N,N-dimethyl-p-toluidine,N,N-dimethyl aniline, ferric ethylene dinitrilotetraacetate,polyethylene polyamine, N-methylethanolamine, or 2,2′(p-tolyimino)diethanol.
 16. A method as recited in claim 1, wherein the multipartcomposition further includes a radiopaque filler contained in at leastone of the initially separate parts that comprises at least one of abismuth salt, silver, a silver salt, a barium salt, a strontium salt, atungsten-containing compound, or titanium dioxide.
 17. A method asrecited in claim 1, wherein the multipart composition further includesat least one antimicrobial agent contained in at least one of theinitially separate parts.
 18. A method for filling and sealing a rootcanal during or following an endodontic procedure comprising: providinga tooth that includes an access hole drilled into and extending throughthe crown of the tooth, said access hole providing access to at leastone root canal of the tooth that has been cleaned by an endodonticprocedure; mixing together initially separate parts of a multipartendodontic composition to form a mixed filling and sealing compositionwhich is initially flowable and suitable for placement into a root canalduring a root canal procedure and which hardens over time, the mixedcomposition initially comprising: a polymerizable resin portioncontained in at least one of the initially separate parts and comprisedof a hydrophilic polymerizable adhesive resin included in an amount in arange of about 0.5% to about 30% by weight of the mixed composition andthat is at least one of a hydrophilic methacrylate capable of bonding todental tissue found within a root canal and which includes one or moremethacrylate ester linkages, wherein at least a portion of the at leastone methacrylate is substituted with at least one hydrophilic group inaddition to the one or more methacrylate ester linkages, wherein the atleast one hydrophilic group comprises at least one of an oxysulfurradical, borate radical, carboxyl radical, nitro radical, or cyanoradical, and at least one diluent polymerizable resin included in anamount in a range of about 10% to about 70% by weight of the mixedcomposition; and a two-part chemical cure system comprised of: at leastone peroxide-based component contained in at least one of the initiallyseparate parts; and at least one amino component contained in at leastone other of the initially separate parts that does not contain theperoxide-based component; wherein the two-part chemical cure system,upon mixing the initially separate parts together, causes at least aportion of the polymerizable resin portion to polymerize over a periodof time; introducing the mixed composition into the at least one rootcanal of the tooth by means of a narrow diameter cannula sized to fitwithin the root canal and in fluid communication with a high pressurehydraulic system in order for the hydrophilic mixed composition topenetrate into and wet lateral canals and fissures which extend from themain root canal; and allowing the mixed composition to at leastpartially polymerize and harden within the root canal.
 19. A method asrecited in claim 18, wherein the multipart composition includes thepolymerizable resin portion that consists essentially of (i) the atleast one of a methacrylate substituted with at least one of anoxysulfur radical, borate radical, carboxyl radical, nitro radical, orcyano radical so as to readily bond to hydrophilic dental tissue foundwithin a root canal and (ii) the at least one diluent monomer, which isselected from the group consisting of a hydrophilic alkyl acrylate, ahydrophilic alkyl methacrylate, a hydrophilic hydroxyalkyl methacrylate,a hydrophilic aminoalkyl methacrylate, and bisphenol-A-diglycidyldimethacrylate.
 20. A method for filling and sealing a root canal duringor following an endodontic procedure comprising: providing a tooth thatincludes an access hole drilled into and extending through the crown ofthe tooth, said access hole providing access to at least one root canalof the tooth that has been cleaned by an endodontic procedure; mixingtogether initially separate parts of a multipart endodontic compositionto form a mixed filling and sealing composition which is initiallyflowable and suitable for placement into a root canal during a rootcanal procedure and which hardens over time, the mixed compositioninitially comprising: a polymerizable resin portion that consistsessentially of (i) at least one of an acrylate or methacrylate whichincludes one or more acrylate and/or methacrylate ester linkages andwhich is substituted with at least one hydrophilic group in addition tothe one or more acrylate and/or methacrylate ester linkages, wherein theat least one hydrophilic group comprises at least one of an oxysulfurradical, borate radical, carboxyl radical, or nitro radical so as toreadily bond to hydrophilic dental tissue found within a root canal and(ii) at least one diluent monomer selected from the group consisting ofa hydrophilic alkyl acrylate, a hydrophilic alkyl methacrylate, ahydrophilic hydroxyalkyl methacrylate, a hydrophilic aminoalkylmethacrylate, and bisphenol-A-diglycidyl dimethacrylate; and a two-partchemical cure system comprised of: at least one peroxide-based componentcontained in at least one of the initially separate parts; and at leastone amino component contained in at least one other of the initiallyseparate parts that does not contain the peroxide-based component;wherein the two-part chemical cure system, upon mixing the initiallyseparate parts together, causes at least a portion of the polymerizableresin portion to polymerize over a period of time; introducing the mixedcomposition into the at least one root canal of the tooth; and allowingthe mixed composition to at least partially polymerize and harden withinthe root canal.
 21. A method for treating a tooth following or during anendodontic procedure comprising: providing a tooth that includes anaccess hole drilled into and extending through the crown of the tooth,said access hole providing access to at least one root canal of thetooth that has been cleaned by an endodontic procedure; mixing togetherinitially separate parts of a multipart endodontic composition to form amixed filling and sealing composition which is initially flowable andsuitable for placement into a root canal during a root canal procedureand which hardens over time, the mixed composition initially comprising:a polymerizable resin portion contained in at least one of the initiallyseparate parts and consisting essentially of a hydrophilic polymerizableadhesive resin that is at least one of a hydrophilic acrylate ormethacrylate capable of bonding to dental tissue found within a rootcanal and which includes one or more acrylate and/or methacrylate esterlinkages, wherein at least a portion of the at least one acrylate ormethacrylate is substituted with at least one hydrophilic group inaddition to the one or more acrylate and/or methacrylate ester linkages,wherein the at least one hydrophilic group comprises at least one of anoxysulfur radical, borate radical, carboxyl radical, or nitro radical;at least one polymerization photoinitiator; and a two-part chemical curesystem comprised of: at least one peroxide-based component contained inat least one of the initially separate parts; and at least one aminocomponent contained in at least one other of the initially separateparts that does not contain the peroxide-based component; wherein thetwo-part chemical cure system, upon mixing the initially separate partstogether, causes at least a portion of the polymerizable resin portionto polymerize over a period of time; introducing the mixed compositioninto the at least one root canal of the tooth; allowing the mixedcomposition to at least partially polymerize and harden within the rootcanal including by irradiating with radiant energy an exposed portion ofthe mixed composition within the root canal in order to polymerize andharden at least a portion of the mixed composition within a period oftime of about 10 seconds to about 1 minute; and filling the access holewith a filling material.
 22. A method as recited in claim 21, whereinthe polymerization photoinitiator comprises at least one of camphorquinone, benzoin methyl ether, 2-hydroxy-2-methyl-1-phenyl-1-propanone,diphenyl 2,4,6-trimethylbenzoyl phosphine oxide, benzoin ethyl ether,benzophenone, or 9,10-anthraquinone.
 23. A method for treating a toothfollowing or during an endodontic procedure comprising: providing atooth that includes an access hole drilled into and extending throughthe crown of the tooth, said access hole providing access to at leastone root canal of the tooth that has been cleaned by an endodonticprocedure; mixing together initially separate parts of a multipartendodontic composition to form a mixed filling and sealing compositionwhich is initially flowable and suitable for placement into a root canalduring a root canal procedure and which hardens over time, the mixedcomposition initially comprising: a polymerizable resin portioncontained in at least one of the initially separate parts and consistingessentially of a hydrophilic polymerizable adhesive resin that is atleast one of a hydrophilic acrylate or methacrylate capable of bondingto dental tissue found within a root canal and which includes one ormore acrylate and/or methacrylate ester linkages, wherein at least aportion of the at least one acrylate or methacrylate is substituted withat least one hydrophilic group in addition to the one or more acrylateand/or methacrylate ester linkages, wherein the at least one hydrophilicgroup comprises at least one of an oxysulfur radical, borate radical,carboxyl radical, or nitro radical; and a two-part chemical cure systemcomprised of: at least one peroxide-based component contained in atleast one of the initially separate parts; and at least one aminocomponent contained in at least one other of the initially separateparts that does not contain the peroxide-based component; wherein thetwo-part chemical cure system, upon mixing the initially separate partstogether, causes at least a portion of the polymerizable resin portionto polymerize over a period of time; introducing the mixed compositioninto the at least one root canal of the tooth; applying additionalpressure to the mixed composition after introducing it into the rootcanal, wherein the application of additional pressure is carried out bymeans of inserting an elastomeric plug into the access hole and applyingforce to the plug in order to exert fluid pressure onto the mixedcomposition, the elastomeric plug being sized so as to form asubstantially fluid-tight seal between the plug and dental tissuesurrounding the access hole; allowing the mixed composition to at leastpartially polymerize and harden within the root canal; and filling theaccess hole with a filling material.